Magnetic shield for electric motors



2 Shets-Sheet 1.

(No Model.)

G. J. VAN DEPOELE.

MAGNETIC SHIELD FOR ELECTRIC MOTORS.

Patented 1000.16, 1890.

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I I M I :HJ r

! rum I Charles J VZznDepoeZe (No Model.) 2 Sheets-Sheet 2. 0. J. VANDEPOELE.

MAGNETIC SHIELD FOR ELECTRIC MOTORS. No. 443,019. Patented Dec. 16,1890.

Charles I VanD6peZe V 0 w m M M a W o M m e M .II u m 9 3v 0 dl o Q0 w lo a u c o m I 0 e o I 1 l| 9 V Q P o 1| 9 o w il 0 O l l INN o o o 10 B0 .4. o J W llilli, w a o 9 A. W I)! 0 v Q r l Q In 1 11] 1 9 Q 1 UNITEDSTATES PATENT OFFICE.

CHARLES J. VAN DEPOELE, OF CHICAGO, ILLINOIS.

MAGNETIC SHIELD FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters l atent No. 443,019, datedDecember 16, 1890.

Application filed August 4, 1887. Serial No. 246,098. (No model.)

To (tZZ whom it may concern:

Be it known that I, CHARLES J. VAN Dn POELE, a citizen of the UnitedStates, residing at Chicago, in the county of Cook, State of Illinois,have invented certain new and useful Improvements in Magnetic Shieldsfor Electric Motors, of which the following is a description. My presentinvention relates to improvements in electric railways, and is in thenature of an arrangement for the protection of whatever may be carried011 cars driven in whole or in part by electric machinery from themagnetizing effects of the lines of force radiating from thefield-magnets of the n10- tor.

As an electric apparatus comes more generally into use it is found thatthe watches of passengers as well as those of the train-men are liableto become so thoroughly magnetized by the magnetic influence of themotor as to be seriously and permanently injured, and in many instancesrendered practically useless. Hence great objection is made to the useand introduction of electric railways on the ground thatwatches as wellas all fine machinery using steel parts are liable to a species ofinjury from magnetization which is not perceptible to the eye and almostbeyond cure, the existence of the difficulty not being perceptibleuntil, if a watch, it has become so inaccurate that in operating arailway it would be very dangerous indeed and apt to cause accidents.The difficulties arising from these sources are altogether obviated byinclosing the motor in a sheet-iron casing or in any convenient mannerinterposing an iron shield between the motor and the interior of thevehicle.

In the accompanying drawings, Figure 1 is a perspective view of the endportion of the car provided with my anti-magnetic shield, the motorbeing mounted upon the front platform. Fig. 2 is a plan View of a car inwhich the motor is mounted in the center and surrounded by a magneticshield. Fig. 3 is an elevation, partly in section and partlybrokcn away,showing a portion of a car having its motor mounted below and a shieldagainst its under side. Fi 4 is a view in elevation showing a motor andits inclosing-shield.

Similar letters denote like parts throughout.

Upon the front platform A of the car B is mounted a motor C, thearmature-shaft thereof being in mechanical connection with thecarrying-wheels in any convenient manner.

D is a shield of iron interposed between the motor and the end of thecar for the purpose of preventing the lines of force surrounding andemanating from all electric apparatus from passing into the ear andaffecting the watches of the passengers. The shield D may be in onepiece or continuous, but as shown is in three separate pieces separatelyattached to the door and to the side portions alongside the door. It isalso convenient to place a magnetic shield below the motor, thesheet-iron E upon the floor of the platform of the car being providedfor that purpose. In this manner the magnetic lines of force radiatingfrom the motor are entirely isolated and prevented from spreading exceptin directions where they can do no injury.

In Fig. 2 the motor 0 is shown at about the center of an open car F, oneof the seats beon the inside with sheet-iron, a suitable door 9 beingprovided, through which access can be had to the working parts of themotor. IVhen it is found desirable to mount the motor directly upon thetruck of a car, as shown in Fig. 3, in which the. motor O is secured toand carried by the truck I, I attach a magnetic shield so that it shallextend over and entirely cover the motor. I find that a very simple andeffectual plan is to cover the under, upper, or lower side of the entirefloor of the car with sheetiron, as shown at J, by which means the entryof magnetic lines into the car is entirely prevented and the mostperfect protection is obtained.

It will be understood that my invention is not limited to the watches ofpassengers in streetcars, since I find it applicable as well tostationary motors, dynamos, and other electric apparatus, as the same isfrequently used in factories where numbers of persons are employed, andthe prevention of injury to their watches and to fine steel articlesbeing produced by electric apparatus, whether moving or stationary, isthe main object I have in view.

In Fig. 4 is shown a stationary motor C standing upon a magnetic shield1i, surrounded by a similar anti-magnetic casing L, provided with doorI), and covered by a sheetiron top M, hinged to the casing L in anyconvenient manner. By these means the motor is so completely inclosedthat the radiation of magnetic lines beyond the shield is entirelyprevented, while the motor itself is at any time readily accessible. Myinvention does not, however, extend to or include an organizationembodying a magnetic shielding medium which constitutes a part of themotor and the field-magnet system thereof.

The slight modifications necessary to adapt my invention tocircumstances different from those herein referred to will at oncesuggest themselves to a competent electrician, and are therefore withinthe scope of my invention.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

1. The combination, with an electric motor and a vehicle upon which saidmotor is mounted, of a sheet-iron casin g constituting a magnetic shieldand permanently interposed between the motor and the interior thereof,whereby the passage of magnetic lines from the motor to the interior ofthe vehicle is prevented, substantially as described.

2. The combination, with a vehicle and an electric motor mounted thereonfor propelling the same, of a magnetic shield consisting of a partitionor casing of iron permanently interposed between the motor and theinterior of the vehicle whereby the radiation of magnetic lines from themotor to the interior of the vehicle is prevented, substantially asdescribed.

3. The combination, with an electric motor havingapoWen-transmittingdevice connected with its armature-shaft, of a permanent casing entirelyinclosing all the parts of said motor except the power transmittingdevice, thereby preventing the radiation of magnetic lines beyond thecasing in any direction.

In testimony whereof 1 hereto affix my signature in presence of twowitnesses.

CHARLES J. VAN DEPOEL'E.

Vitnesses:

\VILLIAM A. S'rILEs, EvERELL l). STILEs.

